Author Topic: Lyman manual  (Read 746 times)

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Offline The Sodbuster

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Lyman manual
« on: January 21, 2007, 06:18:14 AM »
I've noticed while going through some of the load data in the latest Lyman manual that there's quite a variety of pressure data.  For some cartridges, pressure is given in CPU; for others, PSI; and for others, no pressure data is given.  To make things more confusing, for a given cartridge, some loads might give CPU and others PSI.  And in several cases, for a given bullet in a given cartridge, some powders will list pressure in CPU and others in PSI and some powders have no pressure data.

This strikes me as pretty sloppy.  I understand they might have some older data in CPU and for whatever reason see no point in revising it.  But there should be consistency within a cartridge.  Most of these companies go 5 years or better between manuals.  I would hope in the new manuals coming out (Hornady right now and Nosler this summer) that they provide pressure data and have it all in PSI.  Heck even some gun writers have the equipment necessary to measure chamber pressures.

Offline bearfat

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Re: Lyman manual
« Reply #1 on: January 21, 2007, 06:28:23 AM »
Another thing I've noticed with Lyman (with the rounds I reload) is they allow the highest amount of powder for their max loads compared to the Speer, Nosler, Sierra, Hornady manuals I have.

Just out of curiosity I would guess or rank how old and long they have been in business like this:

Lyman   Hornady   Sierra   Speer   Nosler

I have no idea if I am accurate.
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Offline wncchester

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Re: Lyman manual
« Reply #2 on: January 22, 2007, 03:39:24 AM »
Sod, the method of pressure, CUP vs PSI, are for reference only, as a matter of comparision.  It is not hard data for us to accept as gospel. 

Lyman has been in this business MUCH longer than anyone else and they simply don't want to toss out tons of good info simply because SAMMI has changed methods of recording pressures.  It would cost them a small fortune to re-shoot all those loads to get the PSI values.  I'm glad to have that extra info myself even it the units aren't the same.

Fact is, none of us can safely take any max, or even near max, load and fire it.  We MUST start lower and move only up with intelligent caution.  As "bearfat" notes, even the various manuals get different results in their guns. 

So, don't get too wrapped up in units of pressure.  Just use those numbers as general info for consideration 'cause that's all it is.
Common sense is an uncommon virtue

Offline Catfish

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Re: Lyman manual
« Reply #3 on: January 23, 2007, 09:21:52 AM »
Don`t get hung up with the max presures and what the book say or calls them. The presures they give are for the loads they shot, the cases the powder lot and the primers. Presures go up or down when you change brands of primers, manufactures of brass or lots of powder. I use to load H-4831 powder in .270 Wim. cases behind a 110 gr. Serria bullet. I could load 64 grs. in some of the commerical cases but in the 06 mil. cases I necked down I could only get 57 or 58 grns. in the cases. Had I been useing a faster burning powder and put the same charge in these case the presure would go through the roof, litteraly, in the reformed cases. You have to use some sence when loading your own ammo.

Offline goodconcretecolor

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Re: Lyman manual
« Reply #4 on: January 28, 2007, 08:47:58 AM »
I have to agree with wnnchester. Lyman has too much invested in the reams of data they have just to throw it away. As a long time reloader(20 years) and an engineer by profession, the Lyman manual is one of my favorites. I recommend that any serious reloader keep a current edition of the Lyman handbook on their bookshelf and refer to it often. I always recommend that a new reloader have the manual from the manufacturer of the bullet(s) that they shoot, one of the "loadbooks" for their caliber and the Lyman handbook as a start.

Offline OLDHandgunner

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Re: Lyman manual
« Reply #5 on: January 28, 2007, 02:02:39 PM »
I really use the Lyman #48 book, Lyman Pistol & Revolver, & Lyman Cast Bullet Books more than any other books. They also have alot of reloading info for the beginners  & for us oldtimers. My first loading manual back in the mid 60's was a Lyman. Still have it.

Offline The Sodbuster

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Re: Lyman manual
« Reply #6 on: January 29, 2007, 02:11:01 AM »
Quote
Sod, the method of pressure, CUP vs PSI, are for reference only, as a matter of comparision.

That's my point!  It's there for comparison, to see where loads fall on the pressure continuum with respect to one another.  But I can't compare them if some loads for a given bullet are listed in CUP and others in PSI.  It's apples and oranges. 

If all the data for one cartridge is in CUP, I'm not asking them to chuck it and retest everything.  I just want consistency within a given cartridge.  Hey I like the Lyman manual and will continue to use it.  But there's room for improvement.  Of course, some reloading authorities don't give any pressure data for their loads.